Quantitation of Lp-PLA2 activity in serum or plasma
2 - 4 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Serum (preferred) or plasma
Red-top tube, gel-barrier tube, or lavender-top (EDTA) tube
Separate serum or plasma from cells as soon as possible (within two hours).
Refrigerate, stable for 14 days. Stable at room temperature for 24 hours and frozen up to 18 months. Ship refrigerated on cool packs.
Fasting is not required.
Hemolyzed samples; excessive turbidity; clots in samples
The PLAC® test for Lp-PLA2 Activity is an enzyme assay for the in vitro quantitative determination of Lp-PLA2 (lipoprotein-associated phospholipase A2) activity in EDTA plasma and serum. Lp-PLA2 activity is to be used in conjunction with clinical evaluation and patient risk assessment as an aid in predicting risk of coronary heart disease (CHD) in patients with no prior history of cardiovascular events.
Spectrophotometric, enzymatic assay
• Reduced Risk: <225 nmol/min/mL
• Increased Risk: ≥225 nmol/min/mL
Lp-PLA2 is a calcium-independent phospholipase A2 enzyme that is associated with both low-density lipoprotein (LDL) and, to a lesser extent, high-density lipoprotein (HDL) in human plasma and serum1 and is distinct from other such phospholipases such as cPLA2 and sPLA2.2,3 Lp-PLA2 is produced by macrophages and other inflammatory cells and is expressed in greater concentrations in advanced atherosclerotic lesions than early-stage lesions.4,5
Several lines of evidence suggest that oxidation of LDL plays a critical step in the development and progression of atherosclerosis.6,7 Lp-PLA2 participates in the breakdown of oxidized LDL in the vascular wall by hydrolyzing the oxidized phospholipid, producing lysophosphatidylcholine and oxidized free fatty acids, both of which are potent pro-inflammatory products that contribute to the formation of atherosclerotic plaques.8-10
Lp-PLA2 has demonstrated modest intra- and inter-individual variation, commensurate with other cardiovascular lipid markers and substantially less variability than high sensitivity C-reactive protein (hs-CRP). In addition, Lp-PLA2 is not elevated in systemic inflammatory conditions, and may be a more specific marker of vascular inflammation. The relatively small biological variation of Lp-PLA2 and its vascular specificity are of value in the detection and monitoring of cardiovascular risk.11-13
|Order Code||Order Code Name||Order Loinc||Result Code||Result Code Name||UofM||Result LOINC|
|123283||Lp-PLA2 Activity||86951-1||123284||Lp-PLA2 Activity||nmol/min/mL||86951-1|
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